diff --git a/lnaddr.py b/lnaddr.py
index 2d88a87..094f4a5 100755
--- a/lnaddr.py
+++ b/lnaddr.py
@@ -249,6 +249,16 @@ def __str__(self):
         )
 
 def lndecode(a, verbose=False):
+    # When calling secp256k1: 
+    # Uses ALL_FLAGS if available.
+    # Falls back to FLAG_VERIFY if ALL_FLAGS is missing.
+    # Falls back to no flags (safe default) if neither constant exists.
+    flags = None
+    if hasattr(secp256k1, "ALL_FLAGS"):
+        flags = secp256k1.ALL_FLAGS
+    elif hasattr(secp256k1, "FLAG_VERIFY"):
+        flags = secp256k1.FLAG_VERIFY
+
     hrp, data = bech32_decode(a)
     if not hrp:
         raise ValueError("Bad bech32 checksum")
@@ -345,7 +355,7 @@ def lndecode(a, verbose=False):
             if data_length != 53:
                 addr.unknown_tags.append((tag, tagdata))
                 continue
-            addr.pubkey = secp256k1.PublicKey(flags=secp256k1.ALL_FLAGS)
+            addr.pubkey = secp256k1.PublicKey(flags)
             addr.pubkey.deserialize(trim_to_bytes(tagdata))
         else:
             addr.unknown_tags.append((tag, tagdata))
@@ -372,7 +382,7 @@ def lndecode(a, verbose=False):
         if not addr.pubkey.ecdsa_verify(bytearray([ord(c) for c in hrp]) + data.tobytes(), addr.signature):
             raise ValueError('Invalid signature')
     else: # Recover pubkey from signature.
-        addr.pubkey = secp256k1.PublicKey(flags=secp256k1.ALL_FLAGS)
+        addr.pubkey = secp256k1.PublicKey(flags)
         addr.signature = addr.pubkey.ecdsa_recoverable_deserialize(
             sigdecoded[0:64], sigdecoded[64])
         addr.pubkey.public_key = addr.pubkey.ecdsa_recover(